Add some debug messages to the riscv64 build patch hack.

To help figure out what goes wrong on LUCI.

Test: lunch riscv64-trunk_staging-eng
      art/tools/buildbot-build.sh --target --installclean
Bug: 309766445
Change-Id: Idbc45bdd7cb2b843c95b7bbe58bd6e0c2ad54bbc
1 file changed